Packing-ring for pistons.



No. 733,665. 'PATENTED JULY 14, 1903.

H. LEMP.

PACKING RING FOR PISTONS.

APPLICATION IILED NOV. 21, 1901.

witnesses: Irv oenbo Hermann Lem la mgg, p

fitty.

Urvrrsn STATES Patented July 14, 19031 PATENT OFFICE.-

HERMANN LEMP, OF LYNN, MASSACHUSETTS, ASSIGNOR TO ELIHU THOMSON, OF.SWAMPSCOTT, MASSACHUSETTS.

PACKING-RING FOR PISTONS.

SPECIFICATION forming part of Letters Patent No. 733,665, dated July 14,1903.

Application filed November 21, 1901. Serial No. 83,183. (No model.)

To (0M whom it may concern:

Be it known that I, HERMANN LEMP, a citizen of the United States,residing at Lynn, in the county of Essex, State of Massachusetts, haveinvented certain newand useful Improvements in Packing-Rings forPistons, of which the following is a specification.

To fit piston-rings as ordinarily constructed requires a skilledworkman, and the results obtained are not always satisfactory unless theman has had particular training in this branch of work. The difficultyis to make the ring in such manner that it will make a close fit withthe piston-body and at the same time have a'perfectly-true periphery forengagement with the inner wall or surface of the cylinder. The rings arespringy, and thereforea joint has to be provided, and particulardifficulty is experienced in making this joint so that no leak will takeplace at that point when the piston is operatively mounted in acylinder. A number of rings are usually employed, and great difficultyis experienced in making the several joints and assembling the rings insuch manner that no leak will take place when the piston is inoperation. Good practice dictates that the rings shall be prevented fromrotating by the use of akey, thus increasing the cost of manufacture.When the pistons are large, the difficulty of fitting the rings is lessthan where they are small, for obvious reasons.

I have discovered that by using laminated punchings the carefully andaccurately fitted joints may be dispensed with, and, furthermore, thatthe machine-work on the ringssuch as turning, for example-can beobviated.

In the accompanying drawings, which illustrate an embodiment of myinvention, Figure 1 is a sectional view of an engine-cylinder, showingthe piston in elevation. Fig. 2 is a vertical section of the. piston.Fig. 3 is a perspective view of one of the followerrings. Fig. 4 is aperspective view of one of the packing-rings. Fig. 5 is a detail view,in horizontal section, of the piston and rings. Fig. 6 is a similar viewof a slight modification. Fig. 7 is a detail View of an ordinarypiston-ring in the process of construction,

and Fig. 8 is a detail view showing the lastmentioned ring as it appearswhen in use.

Various kinds of joints for piston-rings have been devised. The oneshown in Figs. 7 and 8 is a common one and is used to illustrate thecharacter of work necessary in properly fitting a ring.

1 represents an ordinary cast-iron ring having a finished periphery andbore, also finished sides. The diameter of the ring as originally formedis somewhat larger than that of the cylinder-bore. The sides of the ringare slotted radially at 2 and 3, the lefthand side of the slot 2coinciding with the right-hand side of the slot 3. Completing the slotsalso splits the ring, and the surfaces 4. and 5 will engage with eachother when the ring is compressed and ready for use, as in Fig. 8. Steamor gas, as the case may be, can enter the slots 2 and 3, so that thereal restriction to the passage thereof is found in the joint formedbetween the surfaces 4 and 5. This joint is shunted by a second jointi.e., the one between the ring and the piston-bodyso that if the ring doesnot make a very tight fit the steam or gas will pass from the slot 2through the said space or joint to the slot 3.

My improved packing is made of laminated I punchings, and I have foundlow-grade machine-steel one thirty-second of an inch thick to besatisfactory for the follower,while for the piston-ring untemperedtool-steel is used, although my invention is not to be construed asbeing limited to this precise kind and thickness of stock. Two kinds ofrings 6 and7 are employed, the former being termed a follower and thelatter a packing ring. The inside diameter of the follower-ring is suchthat the ring will make a tight fit with the body 8 of the piston, sothat no opportunity is afforded for the steam or gas to leak at thispoint. I have shown a trunk-piston; but the invention can be used inconnection with pistons of any suitable construction. The outsidediameter of the follower-ring is slightly less than the internaldiameter of the cylinder. The ring is made with an ordinary punch anddie, and no finishing of any character is required. Each packing-ring ispunched a trifle larger than the bore of the cylinder, in the particularcase illustrated one sixtyfourth of an inch larger. The opening in thecenter of the ring is somewhat greater than the diameter of thepiston-body. In the present instance a clearance of one thirty-second ofan inch is provided. The ring is slotted at 9, the sides of the slotbeing perpendicular to the plane of the ring. No attempt is made tofinish the ring after punching, either by turning the periphery or boreor in any way cutting the slot 9. Thus it will be seen that by using agood punch and die both of the rings may be applied to the pistonwithout extra machine-work.

The piston-body Sis provided with a shoulder at its lower end, andsurrounding the body and resting on the shoulder are the rings 6 and 7.In assembling I prefer to alternate the rings, so that a split orpacking ring is located between two follower-rings. The slots 9 in thepacking-rings should be arranged to break joint. In Fig. l the jointsare shown as staggered on the front of the piston-body, this being donefor the purpose of illustration; but in practice the joints arepreferably located at various points around the piston. The rings areheld in place against the shoulder by the end plate 10, the latter beingsecured by the bolt 11. The end plate is shouldered on the under side,which shoulder fits into a corresponding depression in the pistonbody.The piston is connected to the crank by the rod 12 in the ordinarymanner.

Referring to Fig. 5, the rings are shown on an enlarged scale and thespace between the packing-rings '7 and the piston-body 8 is shown on anexaggerated scale for the purpose of illustration.

In Fig. 6 the follower-ring 6 is split, as well as the packing-ring 7.This enables me to put the rings on a piston where the body has not beenaccurately turned.

The pistons illustrated are of small size, and being of the trunkvariety, where no guides are used for the piston or connecting rod, therings cover the entire length; but for larger pistons or pistons havingrods and guides the rings may cover only a portion of the body.

The opportunity for steam or gas to leak from one end of the piston. tothe other is reduced to a minimum by reason of the close association ofthe packing and follower rings when clamped in place. The only passagesopen to the steam or gas are the very small spaces 9, furthercommunication being prevented by the follower-rings, which bear on theflat sides of the packing-rings. Again,

the friction contact or fit between the follower-rings and thepiston-body will prevent steam or gas from passing at that point. Whensplit follower-rings are used, the spaces formed therein should ofcourse be staggered with respect to those of the adjacent packingrings.In actual. service it has been found that the rings wear to a goodbearing-surface and that the interior of the cylinder becomes smooth andpolished. It has also been found that the leaking around the piston hasbeen materially reduced.

In an engine provided with three pistons the cost of nine turned rings,three for each piston, was one dollar and sixty cents, whereas with myimproved rings the cost for three pistons was only eight cents.

The advantage of my improved structure is twofold-first, reduced firstcost and consequent cheapness in replacing, and, second, greaterefficiency on account of the reduction in steam or gas leakage.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is

1. In a piston-packing, the combination of a cylindrical body having aseat, a plurality of split non-overlapping laminated springmetalpacking-rings which surround the body and are separated therefrom by aspace which permits the rings to expand and contract slightly, aplurality of laminated-metal follower-rings which also surround the bodyand are in frictional engagement therewith, and a head for securing therings in place.

2. In combination, a piston-body, a plurality of split packing-ringspunched out of laminae and making a loose fit with the pistonbody, thejoints in said rings being staggered, follower-rings also punched out oflamina; and arranged to separate the adjacent packin g-rin gs, the saidfollower-rings being closely fitted to the piston-body, and a meanscommon to the packing and follower rings for securing them in place.

3. In combination, a piston-body, a plurality of split packing-ringsmade of laminze and arranged to loosely surround the piston-body, aplurality of split follower-rings also made of laminae and arranged tomake a tight fit with the piston-body, the joints in the packing andfollower rings being staggered, and means for firmly clamping the sidesof one ring against the sides of adjacent rings to prevent leakage.

In witness whereof I have hereunto set my hand this 18th day ofNovember, 1901.

HERMANN LEMP.

WVitnesses:

DUGALD MoK. MCKILLOP, JOHN A. McMANUs.

